1. Field of the Invention
The present invention relates to a musical sound signal synthesizer and a method for synthesizing musical sound signals, which synthesizer is used for various units generating a musical sound, such as an electronic musical instrument, a game apparatus, and a personal computer.
2. Description of the Related Art
In known such musical sound signal synthesizers, a modulation system, such as a phase modulation and a frequency modulation, has been employed to form harmonic components to synthesize musical sound signals.
In such synthesizers, to obtain full harmonic components, phase information is inputted in a sine wave table, which outputs waveform information representing a sine waveform, which information is fed back to the sine wave table as a piece of phase information.
With conventional synthesizers, however, peculiar waveforms signals representing waveforms such as square waves cannot be produced, so that various waveforms are not generated, while generating musical sound waveform signals which change from sine waveforms to sawtooth-like waveforms.
In view of the foregoing, it is an object of the present invention to provide a musical sound signal synthesizer with a simple construction, in which complex musical sound waveform signals including many harmonics can be synthesized.
To achieve the above-mentioned object, the musical sound signal synthesizer of the present invention comprises: a waveform generator generating waveform information representing a required waveform based on supplied phase information, a nonlinear transformer transforming nonlinearly the waveform information generated by the waveform generator, and a calculator calculating phase information corresponding to a phase of a musical sound signal to be generated and the waveform information nonlinearly transformed and supplying the calculated phase information to the waveform generator.
In this case the nonlinear transformer is constituted by a polarity transformer inputting information with a positive and a negative polarity and transforming the inputted information into information with one polarity.
According to the above-mentioned construction, the waveform information generated by the waveform generator is transformed nonlinearly by the nonlinear transformer, and the nonlinearly transformed waveform information and the phase information corresponding to the phase of the musical sound signal to be generated are calculated, so that the calculated information is fed back to the waveform generator.
As a result thereof, the phase information to be supplied to the waveform generator changes complexly, so that the waveform, which is represented by waveform information outputted from the waveform generator, becomes peculiar for a musical sound signal synthesized by modulation technique.
Also, the musical sound signal synthesizer of the present invention comprises: a waveform generator generating waveform information representing a required waveform based on supplied phase information, a nonlinear transformer transforming nonlinearly phase information to be supplied to the waveform generator, and a calculator calculating phase information corresponding to a phase of a musical sound signal to be generated and the nonlinearly transformed phase information and supplying the calculated phase information to the waveform generator.
In this case, the nonlinear transformer is constituted by, for example, polarity transformer inputting information with a positive and a negative polarity and transforming the inputted information into information with one polarity.
According to the above-mentioned construction, the phase information to be supplied to the waveform generator is transformed nonlinearly and the nonlinearly transformed phase information is fed back to the phase information corresponding to the phase of the musical signal to be generated.
As a result thereof, the phase information to be supplied to the waveform generator changes complexly, so that the waveform, which is represented by waveform information outputted from the waveform generator, becomes peculiar for a musical sound signal synthesized by modulation technique.
According to the above-mentioned inventions, the complex and peculiar musical sound waveform signals including many harmonics in a peculiar form can be synthesized with a simple construction, thereby meeting the demand of the user in that various waveforms can be generated.